James david murphy



June 19, 1928. 1,674,054

J. D. MURPHY ESCAFEMENT MECHANISM IN TYPEWRITING MACHINES Filed July 25; 1925 .g- W L WMW Patented June 19, 1923;.

? unrr "earn atest rarest entree.

' JAMES DAVID 'MURPHY, OF MONTREAL, QUEBEC, CANADA.

ESCAPEMENT MECHANISM IN TYPE-WRITING MACHINES.

Application filed July 1925. Serial No. 46,067.

The invention relates to escapement mechanism 1n typewriting machlnes, described in the present specificationand illustrated in the accompanying drawings that form' an explanation in detail of an acceptable :form of the invention.

The objects of the invention are tofacilitate the operations in typewriting whereby the speed of the operation is accelerated; to limit the periods of spacing the speed of g the spacing dog; to reduce the noise due to this particular part-and insureevenness in the movements between letters; to avoid the interference-0ftype bars through. the rapid.

motion in typing; to accomplish these pur poses at a low cost, so as to maintam the price of machines at a low figure; and gen Figure 1 is a front elevation of the escape ment mechanism of a typewriting machine. Figure2 is a rear elevation of the same.

' Figure 3 is an enlarged detail of the moving panel showing the invention;

Figure 4 is a detail showing the relative positionsof the moving and stationary dogs at the end of a spacing stroke.

Figure 5 is a detail-showing the relative positions of the dogs at the beginning of a stroke. I V

Figure 6 is an end elevation corresponding to the positions shown in Figure4. r

Figure 7 is an end elevation corresponding to the positions shown in Figure 5.

Likenumerals' of reference indicate corresponding parts in the various figures.

Referring to the drawings, the dog rocker 17 is pivoted in the stationary bracket 21 adapted to be secured to the frame of the typewriting machine not shown.

The spacing wheel 20 is rotatablv mounted on the stationary bracket 21 and is formed with the spaced teeth .22 and carries the pawl and ratchet mechanism 23. which is all ordinary construction in the art. including typewriting machines.

The rack 24 engages the ratchet 23 and the spring 27 pulls on the carriage 28 to which the rack 24 is secured, consequently when the carriage 28 is released by the lifting of a key following the printing of a letter, the rack 24 turns the ratchet 23 and through the pawl 29 the spacing wheel 20 is rotated.

The rocking dog rocker 17 carries the pawl 26 stationary with the bracket 17 and the moving pawl journalled on the pivot 3 0 at its pivot bearing 12, said pivot being secured in the dog rocker 17 below the pawl 16 and slightly in advance of said pawl.

The movingpawl 10 is preferably formed with the neck 14 swelling into the body 31 the latter having the curved back 82 and substantially straight face 11 from which the eye lug 13 projects near to the outer end of the dog. H i

The spring 16 follows the shape of the back 32 and is'secured to the back of the neck 14 and is sprung out slightly from the back 32 and the spring is secured to the front of the neck 14 and is sprung out from the face 11, and this pawl 10 having thestops 18 and 19, said stop 18 being-in the form of a screw head, having a cam face 38; One stop'19 isa pin projecting from the stationary pawl 26 and the other stop 18 is at the end of the bar which is secured to the rigid bracket 21. e

In the operation of this machine the spring pull on the carriage operates the escapement wheel through the pawl and ratchet mechanism and the rack 24, which is common to many machines on the market, and this operation follows the printing of a character. The downward pressure on the key rocks the dog rocker 1.7 and this releases the moving pawl 10 from engagement with one of the teeth 22, and this moving pawl 22: is immediately released thereby and its place taken by the stationary pawl 26.

The return of the type bar rocks the dog rockerto its original position. meanwhile the spacing has been done. In the next spacing of the machine the moving pawl 10 is carried by a tooth 22 of the spacing wheel against the pull of the spring secured to the stationary bracket 21 at 34. and attached to the moving pawl 10. This movement sends the moving pawl up against the stop 19 and the spring 16 on the back of the pawl hits the said stop 19 having both a cushioning and resilient or rebound action.

The lifting of the key again releases the dog 10 so that it is free to return by its own spring pull to the stop 18 where the cam face slides it into place between two of the teeth 22 and also where the spring 15 hits the stop 18 having exactly the same action of cush ioning and re-acting as the spring on the back of the pawl.

The constant movement of the dog 10 materially reduces the work of operation, and especially in quick typewriting materially facilitates the increased speed. It can hardly be said that it increases the speed so much as facilitating the work of the operator in rapidly playing on the keys, in other words, the spacing mechanism is accelerated though the actual speed in operating the keys must naturally come from the operator.

What I claim is I. In escapement mechanism in typewriting machines, a toothed spacing wheel, an oscillatory member, a dog pivotally mounted on said oscillatory member and brought into action by the movement thereof, cushioning and rebounding means secured to said dog, a stop on said oscillatory member and a stop apart therefrom, said stops being adapted to limit the strokes of said dog and meet said cushioning and rebounding means.

2. In escapement mechanism in typewriting machines, a toothed spacing wheel operatively connected with a spring pulled carriage, a reciprocating dog having a transverse swinging movement and engaging said wheel alternately, a stationary stop, a stop moving transversely with said reciprocating dog springs secured to the front and back of the dog and adapted to operate reciprocally between said stops and a tilting member having a dog engaging said wheel intermittently and carrying the aforesaid dog.

3. In escapement mechanism in typewriting machines, a toothed spacing wheel, a reciprocating dog, a rocking member having a pivot bearing for said dog, stops limiting the strokes of said dog, and rebounding means secured to said reciprocating dog and contacting at the end of each stroke with said stops respectively.

4. In escapement mechanism in typewriting machines, a star wheel, a dog pivotally mounted and oscillating transversely to the wheel in relation to its stroke, a stationary stop having a cam face, a stop, moving transversely with said dog, and springs forming rebounding and cushioning members for said dog and adapted to contact with said stationary stop and said movable stop respectively during the stepping movement of the dog.

5. In escapement mechanism in typewriting machines, a rigid bracket having a rigid stop and pivoting a rocking bracket carrying a stop, a reciprocating dog provided with springs at its sides forming faces and adapted to engage with said rigid bracket stop and said rocking bracket stop and fenning a cushioning member against the aforementioned stops, said rocking bracket carrying a pivot bearing for said reciprocating dog.

6. In typewriting machines, a reciprocating escapement dog having a rounded back and strip springs secured to and,extending along the front and the back in relation to the direction of stepping movements, a tilting member carrying said dog swi'ngin transversely in relation to the movement o said dog, a toothed escapeme ntwheel operated by said dog, and spaced stops engaged respectively by said reciprocating dog in its forward and return strokes and rebounding thercbetween by reason of said springs, one

of said stops being rigid with said tilting member and the other being stationary and having a cam face adapted to swing said tilting member.

7. In typewriting machines, an escapement mechanism having a toothed wheel and comprising a reciprocating dog having a stepping movement between stops facilitated by springs forming a part of the dog on the sides contacting with said stops and effecting rebounding movements, an oscillatory member carrying one of said stops and a pivot bearing for said reciprocating dog, a barcarrying the other and stationary stop, and a stationary dog from said oscillatory member and moving therewith to engage said toothed wheel to allow movement of the reciprocating dog.

Signed at Montreal, Canada, this 11th day of Ju]y,1925.

JAMES DAVID MURPHY. 

